In the case of agricultural apparatuses, moving elements are typically covered covers for safety reasons, in order to protect the operator and other persons. However, because the interior of the apparatus must be accessible for inspection and maintenance purposes, the covers are typically mounted on the apparatus so that they can be removed or pivoted. In order to prevent accidents, the covers are usually opened only by using appropriate tools, which has the disadvantage that they cannot be opened without the appropriate tool. If these tools are not available, work on the apparatus is not possible. It has been proposed to automatically turn off the internal combustion engine of a self-propelled agricultural work machine when a sensor detects that a cover of the work machine has been opened (see e.g. German Patent Document DE 43 09 668 A). An arrangement for detecting an opened cover of a baler, which optionally leads to the PTO shaft of the tractor being deactivated, is described in the subsequently published German Patent Document DE 10 2008 018 541 A1.
In the case of covers, it is considered disadvantageous that they are basically unnecessary for the operation of the apparatus operated by the tractor, but instead only increase the weight and the production costs. In many cases, they are disassembled by the operators in order to make working on the apparatus easier. In addition, despite the presence of covers, 100% protection of the operator is not possible, because, for example, the openings through which the apparatus takes in harvested material (in the case of a bale press, the crop pick-up and the rotor arranged downstream) cannot be covered, because if they were, harvested material could not be fed. Even in this section, however, sometimes there are blockages. Operators often attempt to eliminate these blockages while the apparatus is running, which puts them in great danger.
In British Patent document GB 2 206 662 A, a baler with an emergency stop device is described that can be actively controlled by an operator if he finds himself in a dangerous situation when working on the baler, for example, when clearing a blockage. Nevertheless, this emergency stop device cannot prevent the operator from being injured.
Furthermore, it has been proposed to mount an infrared sensor for detecting the heat of living creatures, motors, etc., on a self-propelled baler, wherein this sensor leads to the deactivation of the baler (see e.g. German Patent Document DE 196 08 014 A1). It has been proposed analogously for an unmanned combine harvester to mount a sensor in a danger zone, wherein this sensor detects living creatures and optionally stops the combine harvester (see e.g. German Patent Document DE 102 44 822 A1). The subsequently published European Patent Application EP 2 106 688 A1 describes a baler that is pulled behind a tractor and whose baling speed is reduced when a sensor detects an obstacle in the direct vicinity of the baler.
European Patent Application EP 1 813 146 A2, viewed as a class-forming patent, describes a combination made from a tractor and a baler, each of which is equipped with an electronic control unit. The control units communicate with each other via a bus, so that the control unit of the baler can instruct the control unit of the tractor to stop the tractor for purposes of wrapping and ejecting a bale. Before starting a baling process, the control of the baler causes the PTO shaft of the tractor to be put in rotation.
The problem forming the basis of the invention is seen in the need for a combination made from an agricultural apparatus and a hauling or towing vehicle in which accidents are prevented or at least made less likely without great expense.